What that distance is, remains to be seen.
The Prosecution leaves it up to your imagination to try this person in the media. While the Police report I linked to suggests that the distance was closer, rather than further.
Her feet where still on the porch, and that porch isn't that wide/long.
What ever distance she was from the door on one side, and what ever distance the gun was from the door on the other side, would be the distance. What would that be? About two to four feet?
Please keep in mind that the above is an observation, not a measurement.Police Report
I observed Decedent McBride lying face up on the porch (feet within a few feet of the front door & head partially obscured by a bush). McBride suffered a large wound to the center of the face/head, consistent with a closer range shotgun blast.